org.jcae.mesh.amibe.ds
Class TriangleVH

java.lang.Object
  org.jcae.mesh.amibe.ds.Triangle
      org.jcae.mesh.amibe.ds.TriangleVH

All Implemented Interfaces:

java.io.Serializable

public class TriangleVH
extends Triangle

A triangular element of the mesh. Instances of this class carry up all topological information required for adjacency relations. Their vertices are contained in a Vertex array, and by convention the local number of an edge is the index of its opposite vertex. A TriangleVH instance has a pointer to its three neighbours through its edges, and knows the local number of opposite edges in their respective triangles. It also stores as a byte array attributes of its three edges.

As local numbers are integers between 0 and 2, a packed representation is wanted to save space. They can be stored within 6 bits, edge 0 is stored in the two least significant bits, edge 1 in next two and edge 2 in next two, so adjPos=(localNumberSymEdge0<<0)+(localNumberSymEdge1<<2)+(localNumberSymEdge2<<4).

Vertices data are colored in black, edges in red and triangles in blue. Triangle a contains these members:

• a.vertex = { A, B, C }
• a.adjacentTriangles = { c, d, b }
• a.adjPos = (0 << 0) + (1 << 2) + (0 << 0) = 2

There are two special cases:

• Boundary edges; a virtual Triangle(outerVertex, v1, v2) is created, and linked to this edge. This triangle has an AbstractHalfEdge.OUTER attribute, and boundary edges have a AbstractHalfEdge.BOUNDARY attribute.
• Non-manifold edges; a virtual Triangle(outerVertex, v1, v2) is also created, and linked to this edge. This triangle has an AbstractHalfEdge.OUTER attribute, non-manifold edge and its symmetric edge have a AbstractHalfEdge.NONMANIFOLD attribute, and other two edges are used to build a circular doubly-linked list of all symmetric edges.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.jcae.mesh.amibe.ds.Triangle

Triangle.List

Field Summary

Fields inherited from class org.jcae.mesh.amibe.ds.Triangle

readable, traits, traitsBuilder, vertex, writable

Constructor Summary

TriangleVH(TriangleTraitsBuilder ttb)
Constructor.

Method Summary

void	clearAttributes(int attr) Resets attributes for all edges of this triangle.
void	copy(Triangle that)
VirtualHalfEdge	getAbstractHalfEdge() Gets a VirtualHalfEdge instance bound to this triangle.
VirtualHalfEdge	getAbstractHalfEdge(AbstractHalfEdge that) Gets a VirtualHalfEdge instance bound to this triangle.
TriangleVH	getAdj(int num) Returns the adjacent TriangleVH through an edge.
int	getAdjLocalNumber(int num) Gets local number of a symmetric edge.
int	getEdgeAttributes(int num) Gets attributes of edge num.
boolean	hasAttributes(int attr) Checks if some attributes of this triangle are set.
void	setAdj(int num, TriangleVH link) Sets TriangleVH adjacent to an edge.
void	setAdjLocalNumber(int num, int pos) Sets local number of a symmetric edge.
void	setAttributes(int attr) Sets attributes for all edges of this triangle.
void	setEdgeAttributes(int num, int attr) Sets attributes of edge num.
java.lang.String	toString()

Methods inherited from class org.jcae.mesh.amibe.ds.Triangle

getGroupId, isReadable, isWritable, setGroupId, setReadable, setWritable

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TriangleVH

public TriangleVH(TriangleTraitsBuilder ttb)

Constructor.

Method Detail

copy

public final void copy(Triangle that)

Overrides:

copy in class Triangle

getAbstractHalfEdge

public VirtualHalfEdge getAbstractHalfEdge()

Gets a VirtualHalfEdge instance bound to this triangle. This method allocates a new VirtualHalfEdge instance and binds it to this triangle.

Overrides:

getAbstractHalfEdge in class Triangle

Returns:

a new VirtualHalfEdge instance bound to this triangle

getAbstractHalfEdge

public VirtualHalfEdge getAbstractHalfEdge(AbstractHalfEdge that)

Gets a VirtualHalfEdge instance bound to this triangle. If argument is null, this method behaves as if no argument was passed. Otherwise, argument is an existing VirtualHalfEdge instance which is bound to this triangle and returned.

Overrides:

getAbstractHalfEdge in class Triangle

Parameters:

that - either null or an existing VirtualHalfEdge instance which is modified

Returns:

a VirtualHalfEdge instance bound to this triangle

getAdj

public TriangleVH getAdj(int num)

Returns the adjacent TriangleVH through an edge.

Parameters:

num - the local number of this edge.

Returns:

the adjacent TriangleVH

setAdj

public void setAdj(int num,
                   TriangleVH link)

Sets TriangleVH adjacent to an edge.

Parameters:

num - the local number of this edge

link - adjacent TriangleVH

getAdjLocalNumber

public int getAdjLocalNumber(int num)

Gets local number of a symmetric edge.

Parameters:

num - edge local number

Returns:

local number of this symmetric edge

setAdjLocalNumber

public void setAdjLocalNumber(int num,
                              int pos)

Sets local number of a symmetric edge.

Parameters:

num - edge local number

pos - local number of symmetric edge

getEdgeAttributes

public int getEdgeAttributes(int num)

Gets attributes of edge num.

Parameters:

num - local edge number

Returns:

attributes of this edge

setEdgeAttributes

public void setEdgeAttributes(int num,
                              int attr)

Sets attributes of edge num.

Parameters:

num - local edge number

attr - attributes to set on this edge

setAttributes

public void setAttributes(int attr)

Sets attributes for all edges of this triangle.

Overrides:

setAttributes in class Triangle

Parameters:

attr - attributes to set on edges

clearAttributes

public void clearAttributes(int attr)

Resets attributes for all edges of this triangle.

Overrides:

clearAttributes in class Triangle

Parameters:

attr - attributes to reset on edges

hasAttributes

public boolean hasAttributes(int attr)

Checks if some attributes of this triangle are set.

Overrides:

hasAttributes in class Triangle

Parameters:

attr - attributes to check

Returns:

true if any edge of this triangle has one of these attributes set, false otherwise

toString

public java.lang.String toString()

Overrides:

toString in class Triangle